POS0111 PILOT STUDY ON EVOKED COMPOUND ACTION POTENTIAL CONTROLLED CLOSED-LOOP SPINAL CORD STIMULATION IN TREATMENT OF RAYNAUD’S PHENOMENON
Authors: V. Schäfer, P. Karakostas, B. Dietz, G. Bara, J. Maciaczyk
Journal: Annals of the Rheumatic Diseases (2023)

<h3>Background</h3> Raynaud's Phenomenon (RP) is an episodically occurring vasospasm of the peripheral arteries that leads to paleness, cyanosis and/or erythema, causing severe pain, sometimes paresthesia and rarely leading to ulceration of the digits and toes. In severe cases, RP patients have physical and functional impairments that substantially affect their ability to work. There are few reports, mostly case series, on the utility of spinal cord stimulation (SCS) to treat RP. However, there is a lack of objective evidence on the physiological effects (e.g., vasodilation) of SCS in this condition. Here, we present clinical outcomes of severe RP patients treated with evoked compound action potential (ECAP)-controlled closed-loop SCS. <h3>Objectives</h3> Severe primary and secondary RP patients can be treated with evoked compound action potential (ECAP)-controlled closed-loop SCS. High-resolution Doppler ultrasound can be used as objective evidence on the physiological effects (e.g., vasodilation) of SCS in RP patients. <h3>Methods</h3> This is a prospective, single-center pilot study to evaluate the effectiveness of ECAP-controlled closed-loop SCS in treating RP. Subjects who meet the inclusion/exclusion criteria, complete all baseline assessments, and sign an informed consent will be considered enrolled (10 in total). Patient outcomes such as Raynaud Condition Score, Raynaud Severity Score, Raynaud Frequency Score, Cochin Hand Function Scale, SHAQ RP VAS, EQ-5D-5L, PGIC and objective peripheral circulation assessments using high-resolution Doppler ultrasound of digital arteries will be reported. <h3>Results</h3> The mean age ± standard deviation (± SD) of the ten patients is 45.5 ± 15.5 years. The mean baseline (± standard error mean (SEM); n = 9) weekly attack frequency was 21.8 ± 5.9 and decreased to 7.7 ± 2.1 after the test phase (n = 9), 4.8 ± 1.7 1-month after implantation (n = 8), 12.4 ± 6.2 3-months after implantation (n = 8) and to 12.6 ± 4.6 6-months after implantation (n = 8). The mean baseline (± SEM; n = 9) severity of attacks was 6.7 ± 0.4 which decreased to 4.9 ± 0.6 after the test phase (n = 9), 4.6 ± 0.9 1-month after implantation (n = 9), 3.8 ± 0.9 3-months after implantation (n = 8) and to 3.3 ± 0.6 6-months after implantation (n = 8). The mean baseline (± SEM; n = 9) Raynaud's condition score was 6.6 ± 0.7 and decreased to 4.4 ± 0.7 after the test phase (n = 9), 4.3 ± 1.0 1-month after implantation (n = 9), 3.4 ± 1.0 3-months after implantation (n = 8) and to 2.6 ± 0.7 6-months after implantation (n = 8). The mean baseline (± SEM; n = 9) for pathological arterial occlusion was 8.6 ± 1.5, with hands warmed in a finger bath. After the trial period (trial-end; n = 9), the mean total score (± SEM) for pathological artery occlusions decreased to 1.9 ± 1.0, and to 2.0 ± 1.1 1-month after implantation (1-month; n = 9), and to 2.1 ± 2.0 3-months after implantation (3-months; n = 8), and to 4.9 ± 2.6 6-months after implantation (6-months; n = 8). The mean baseline (± SEM; n = 9) cochin hand function scale score was 31.6 ± 8.2 and decreased to 24.7 ± 8.0 after the test phase (n = 9), 18.9 ± 7.8 1-month after implantation (n = 9), 19.5 ± 7.5 3-months after implantation (n = 8) and to 17.4 ± 7.7 6-months after implantation (n = 8). The mean patient global impression scale score at 1-month was (± SEM; n = 9) 2.4 ± 0.3, 2.8 ± 0.4 3-months after implantation (n = 8) and decreased to 2.3 ± 0.4 6-months after implantation (n = 8). <h3>Conclusion</h3> This study demonstrates for the first time that RP-related pathological arterial occlusions can be treated effectively with a novel ECAP-controlled closed-loop-SCS system. In conclusion, ECAP-controlled closed-loop-SCS alleviates RP symptoms and improves peripheral blood flow. Longer-term follow up and larger controlled studies are needed to confirm these preliminary results. <h3>REFERENCES:</h3> NIL. <h3>Acknowledgements:</h3> NIL. <h3>Disclosure of Interests</h3> Valentin Schäfer: None declared, Pantelis Karakostas: None declared, Birte Dietz Consultant of: yes I work for Saluda Medical, Employee of: yes I work for Saluda Medical, Gregor Bara: None declared, Jaroslaw Maciaczyk: None declared.